Coating cast iron with lead



Patented Feb. 19, 1929.

UNITED STATES PATENT. OFFICE.

COATING CAST IRON WITH. LEAD.

No Drawing. Application filed. October 2, 1926, Serial No. 139,232, andin Germany November 28, 1925,

There exist a number of processes applied in the art for homogeneouslycoating wrought iron with lead, but the production of a homogeneous leadcoating upon cast iron presents such difficulty that it cannot be saidthat the problem involved has heretofore been solved. The maindifliculty is due to the fact that cast iron, unlike malleable iron,cannot easily be tinned. It follows that those processes which dependupon a'preliminary tinning of malleable iron cannot be applied to castiron. By the present invention cast iron can be homogeneously coatedwith lead in a remarkably smooth and easy manner by first treating thecast iron, which has been thoroughly .cleaned by pickling or a likeoperation, with a solution ofa metallic salt from which the metal isprecipitated by cast iron. As a typical example the use of a copper saltmay be upon it a piece of lead in the usual manner .As soon as thesurface is sufficiently hot the lead flows smoothly and yields ahomogeneous coating of lead of a quality not hitherto achieved. It issimpler to combine the two preparing operations. For this purpose the viron with lead, which comprises treating the cast iron with a coppersalt, a tin salt, and a zinc halide, and melting lead on the surface soprepared. p

2. Process for homogeneously coating cast iron with lead, whichcomprises treating the cast iron with copper sulfate and a mixture v ofprotochloride of tin and zinc chloride, and melting lead on the surfaceso prepared.

3. A process for homogeneously coating cast-iron with lead in which thecast-iron is first treated simultaneously with a mixture ofa coppersalt, a tin salt and zinc halide and in which the lead is then melted onthe surface so prepared. V

4. A process for homogeneously coating cast-iron with lead in which thecast-iron is first treated simultaneously with a mixture of coppersulfate, protochloride of tin and zinc chloride and in which the lead isthen melted on the surface so prepared. v

In testimony whereof I aflix my signature.

' OSKAB SPENGLER.

